lisp/play/solitaire.el

   1 ;;; solitaire.el --- game of solitaire in Emacs Lisp
   2
   3 ;; Copyright (C) 1994, 2003 Free Software Foundation, Inc.
   4
   5 ;; Author: Jan Schormann <Jan.Schormann@rechen-gilde.de>
   6 ;; Created: Fri afternoon, Jun  3,  1994
   7 ;; Keywords: games
   8
   9 ;; This file is part of GNU Emacs.
  10
  11 ;; GNU Emacs is free software; you can redistribute it and/or modify
  12 ;; it under the terms of the GNU General Public License as published by
  13 ;; the Free Software Foundation; either version 2, or (at your option)
  14 ;; any later version.
  15
  16 ;; GNU Emacs is distributed in the hope that it will be useful,
  17 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  18 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19 ;; GNU General Public License for more details.
  20
  21 ;; You should have received a copy of the GNU General Public License
  22 ;; along with GNU Emacs; see the file COPYING.  If not, write to
  23 ;; the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  24 ;; Boston, MA 02111-1307, USA.
  25
  26 ;;; Commentary:
  27
  28 ;; This mode is for playing a well-known game of solitaire
  29 ;; in which you jump pegs across other pegs.
  30
  31 ;; The game itself is somehow self-explanatory.  Read the help text to
  32 ;; solitaire, and try it.
  33
  34 ;;; Code:
  35
  36 (defgroup solitaire nil
  37   "Game of solitaire."
  38   :prefix "solitaire-"
  39   :group 'games)
  40
  41 (defvar solitaire-mode-map nil
  42   "Keymap for playing solitaire.")
  43
  44 (defcustom solitaire-mode-hook nil
  45   "Hook to run upon entry to solitaire."
  46   :type 'hook
  47   :group 'solitaire)
  48
  49 (if solitaire-mode-map
  50     ()
  51   (setq solitaire-mode-map (make-sparse-keymap))
  52   (suppress-keymap solitaire-mode-map t)
  53   (define-key solitaire-mode-map "\C-f" 'solitaire-right)
  54   (define-key solitaire-mode-map "\C-b" 'solitaire-left)
  55   (define-key solitaire-mode-map "\C-p" 'solitaire-up)
  56   (define-key solitaire-mode-map "\C-n" 'solitaire-down)
  57   (define-key solitaire-mode-map [return] 'solitaire-move)
  58   (define-key solitaire-mode-map [remap undo] 'solitaire-undo)
  59   (define-key solitaire-mode-map " " 'solitaire-do-check)
  60   (define-key solitaire-mode-map "q" 'quit-window)
  61
  62   (define-key solitaire-mode-map [right] 'solitaire-right)
  63   (define-key solitaire-mode-map [left] 'solitaire-left)
  64   (define-key solitaire-mode-map [up] 'solitaire-up)
  65   (define-key solitaire-mode-map [down] 'solitaire-down)
  66
  67   (define-key solitaire-mode-map [S-right] 'solitaire-move-right)
  68   (define-key solitaire-mode-map [S-left]  'solitaire-move-left)
  69   (define-key solitaire-mode-map [S-up]    'solitaire-move-up)
  70   (define-key solitaire-mode-map [S-down]  'solitaire-move-down)
  71
  72   (define-key solitaire-mode-map [kp-6] 'solitaire-right)
  73   (define-key solitaire-mode-map [kp-4] 'solitaire-left)
  74   (define-key solitaire-mode-map [kp-8] 'solitaire-up)
  75   (define-key solitaire-mode-map [kp-2] 'solitaire-down)
  76   (define-key solitaire-mode-map [kp-5] 'solitaire-center-point)
  77
  78   (define-key solitaire-mode-map [S-kp-6] 'solitaire-move-right)
  79   (define-key solitaire-mode-map [S-kp-4] 'solitaire-move-left)
  80   (define-key solitaire-mode-map [S-kp-8] 'solitaire-move-up)
  81   (define-key solitaire-mode-map [S-kp-2] 'solitaire-move-down)
  82
  83   (define-key solitaire-mode-map [kp-enter] 'solitaire-move)
  84   (define-key solitaire-mode-map [kp-0] 'solitaire-undo)
  85
  86   ;; spoil it with s ;)
  87   (define-key solitaire-mode-map [?s] 'solitaire-solve)
  88
  89   ;;  (define-key solitaire-mode-map [kp-0] 'solitaire-hint) - Not yet provided ;)
  90   )
  91
  92 ;; Solitaire mode is suitable only for specially formatted data.
  93 (put 'solitaire-mode 'mode-class 'special)
  94
  95 (defun solitaire-mode ()
  96   "Major mode for playing solitaire.
  97 To learn how to play solitaire, see the documentation for function
  98 `solitaire'.
  99 \\<solitaire-mode-map>
 100 The usual mnemonic keys move the cursor around the board; in addition,
 101 \\[solitaire-move] is a prefix character for actually moving a stone on the board."
 102   (interactive)
 103   (kill-all-local-variables)
 104   (use-local-map solitaire-mode-map)
 105   (setq truncate-lines t)
 106   (setq major-mode 'solitaire-mode)
 107   (setq mode-name "Solitaire")
 108   (run-hooks 'solitaire-mode-hook))
 109
 110 (defvar solitaire-stones 0
 111   "Counter for the stones that are still there.")
 112
 113 (defvar solitaire-center nil
 114   "Center of the board.")
 115
 116 (defvar solitaire-start nil
 117   "Upper left corner of the board.")
 118
 119 (defvar solitaire-start-x nil)
 120 (defvar solitaire-start-y nil)
 121
 122 (defvar solitaire-end nil
 123   "Lower right corner of the board.")
 124
 125 (defvar solitaire-end-x nil)
 126 (defvar solitaire-end-y nil)
 127
 128 (defcustom solitaire-auto-eval t
 129   "*Non-nil means check for possible moves after each major change.
 130 This takes a while, so switch this on if you like to be informed when
 131 the game is over, or off, if you are working on a slow machine."
 132   :type 'boolean
 133   :group 'solitaire)
 134
 135 (defconst solitaire-valid-directions
 136   '(solitaire-left solitaire-right solitaire-up solitaire-down))
 137
 138 ;;;###autoload
 139 (defun solitaire (arg)
 140   "Play Solitaire.
 141
 142 To play Solitaire, type \\[solitaire].
 143 \\<solitaire-mode-map>
 144 Move around the board using the cursor keys.
 145 Move stones using \\[solitaire-move] followed by a direction key.
 146 Undo moves using \\[solitaire-undo].
 147 Check for possible moves using \\[solitaire-do-check].
 148 \(The variable `solitaire-auto-eval' controls whether to automatically
 149 check after each move or undo)
 150
 151 What is Solitaire?
 152
 153 I don't know who invented this game, but it seems to be rather old and
 154 its origin seems to be northern Africa.  Here's how to play:
 155 Initially, the board will look similar to this:
 156
 157         Le Solitaire
 158         ============
 159
 160                 o   o   o
 161
 162                 o   o   o
 163
 164         o   o   o   o   o   o   o
 165
 166         o   o   o   .   o   o   o
 167
 168         o   o   o   o   o   o   o
 169
 170                 o   o   o
 171
 172                 o   o   o
 173
 174 Let's call the o's stones and the .'s holes.  One stone fits into one
 175 hole.  As you can see, all holes but one are occupied by stones.  The
 176 aim of the game is to get rid of all but one stone, leaving that last
 177 one in the middle of the board if you're cool.
 178
 179 A stone can be moved if there is another stone next to it, and a hole
 180 after that one.  Thus there must be three fields in a row, either
 181 horizontally or vertically, up, down, left or right, which look like
 182 this:  o  o  .
 183
 184 Then the first stone is moved to the hole, jumping over the second,
 185 which therefore is taken away.  The above thus `evaluates' to:  .  .  o
 186
 187 That's all.  Here's the board after two moves:
 188
 189                 o   o   o
 190
 191                 .   o   o
 192
 193         o   o   .   o   o   o   o
 194
 195         o   .   o   o   o   o   o
 196
 197         o   o   o   o   o   o   o
 198
 199                 o   o   o
 200
 201                 o   o   o
 202
 203 Pick your favourite shortcuts:
 204
 205 \\{solitaire-mode-map}"
 206
 207   (interactive "P")
 208   (switch-to-buffer "*Solitaire*")
 209   (solitaire-mode)
 210   (setq buffer-read-only t)
 211   (setq solitaire-stones 32)
 212   (solitaire-insert-board)
 213   (solitaire-build-modeline)
 214   (goto-char (point-max))
 215   (setq solitaire-center (search-backward "."))
 216   (setq buffer-undo-list (list (point)))
 217   (set-buffer-modified-p nil))
 218
 219 (defun solitaire-build-modeline ()
 220   (setq mode-line-format
 221         (list "" "---" 'mode-line-buffer-identification
 222               (if (< 1 solitaire-stones)
 223                   (format "--> There are %d stones left <--" solitaire-stones)
 224                 "------")
 225               'global-mode-string "   %[(" 'mode-name 'minor-mode-alist "%n"
 226               ")%]-%-"))
 227   (force-mode-line-update))
 228
 229 (defun solitaire-insert-board ()
 230   (let* ((buffer-read-only nil)
 231          (w (window-width))
 232          (h (window-height))
 233          (hsep (cond ((> w 26) "   ")
 234                      ((> w 20) " ")
 235                      (t "")))
 236          (vsep (cond ((> h 17) "\n\n")
 237                      (t "\n")))
 238          (indent (make-string (/ (- w 7 (* 6 (length hsep))) 2) ?\ )))
 239     (erase-buffer)
 240     (insert (make-string (/ (- h 7 (if (> h 12) 3 0)
 241                                (* 6 (1- (length vsep)))) 2) ?\n))
 242     (if (or (string= vsep "\n\n") (> h 12))
 243         (progn
 244           (insert (format "%sLe Solitaire\n" indent))
 245           (insert (format "%s============\n\n" indent))))
 246     (insert indent)
 247     (setq solitaire-start (point))
 248     (setq solitaire-start-x (current-column))
 249     (setq solitaire-start-y (solitaire-current-line))
 250     (insert (format " %s %so%so%so%s" hsep hsep hsep hsep vsep))
 251     (insert (format "%s %s %so%so%so%s" indent hsep hsep hsep hsep vsep))
 252     (insert (format "%so%so%so%so%so%so%so%s" indent hsep hsep hsep hsep hsep hsep vsep))
 253     (insert (format "%so%so%so%s" indent hsep hsep hsep))
 254     (setq solitaire-center (point))
 255     (insert (format ".%so%so%so%s" hsep hsep hsep vsep))
 256     (insert (format "%so%so%so%so%so%so%so%s" indent hsep hsep hsep hsep hsep hsep vsep))
 257     (insert (format "%s %s %so%so%so%s" indent hsep hsep hsep hsep vsep))
 258     (insert (format "%s %s %so%so%so%s %s " indent hsep hsep hsep hsep hsep hsep))
 259     (setq solitaire-end (point))
 260     (setq solitaire-end-x (current-column))
 261     (setq solitaire-end-y (solitaire-current-line))
 262     ))
 263
 264 (defun solitaire-right ()
 265   (interactive)
 266   (let ((start (point)))
 267     (forward-char)
 268     (while (= ?\  (following-char))
 269       (forward-char))
 270     (if (or  (= 0 (following-char))
 271              (= ?\  (following-char))
 272             (= ?\n (following-char)))
 273         (goto-char start))))
 274
 275 (defun solitaire-left ()
 276   (interactive)
 277   (let ((start (point)))
 278     (backward-char)
 279     (while (= ?\  (following-char))
 280       (backward-char))
 281     (if (or  (= 0 (preceding-char))
 282              (= ?\  (following-char))
 283             (= ?\n (following-char)))
 284         (goto-char start))))
 285
 286 (defun solitaire-up ()
 287   (interactive)
 288   (let ((start (point))
 289         (c (current-column)))
 290     (forward-line -1)
 291     (move-to-column c)
 292     (while (and (= ?\n (following-char))
 293                 (forward-line -1)
 294                 (move-to-column c)
 295                 (not (bolp))))
 296     (if (or (= 0 (preceding-char))
 297             (= ?\  (following-char))
 298             (= ?\= (following-char))
 299             (= ?\n (following-char)))
 300         (goto-char start)
 301         )))
 302
 303 (defun solitaire-down ()
 304   (interactive)
 305   (let ((start (point))
 306         (c (current-column)))
 307     (forward-line 1)
 308     (move-to-column c)
 309     (while (and (= ?\n (following-char))
 310                 (forward-line 1)
 311                 (move-to-column c)
 312                 (not (eolp))))
 313     (if (or (= 0 (following-char))
 314             (= ?\  (following-char))
 315             (= ?\n (following-char)))
 316         (goto-char start))))
 317
 318 (defun solitaire-center-point ()
 319   (interactive)
 320   (goto-char solitaire-center))
 321
 322 (defun solitaire-move-right () (interactive) (solitaire-move '[right]))
 323 (defun solitaire-move-left () (interactive) (solitaire-move '[left]))
 324 (defun solitaire-move-up () (interactive) (solitaire-move '[up]))
 325 (defun solitaire-move-down () (interactive) (solitaire-move '[down]))
 326
 327 (defun solitaire-possible-move (movesymbol)
 328   "Check if a move is possible from current point in the specified direction.
 329 MOVESYMBOL specifies the direction.
 330 Returns either a string, indicating cause of contraindication, or a
 331 list containing three numbers: starting field, skipped field (from
 332 which a stone will be taken away) and target."
 333
 334   (save-excursion
 335     (if (memq movesymbol solitaire-valid-directions)
 336         (let ((start (point))
 337               (skip (progn (funcall movesymbol) (point)))
 338               (target (progn (funcall movesymbol) (point))))
 339           (if (= skip target)
 340               "Off Board!"
 341             (if (or (/= ?o (char-after start))
 342                     (/= ?o (char-after skip))
 343                     (/= ?. (char-after target)))
 344                 "Wrong move!"
 345               (list start skip target))))
 346       "Not a valid direction")))
 347
 348 (defun solitaire-move (dir)
 349   "Pseudo-prefix command to move a stone in Solitaire."
 350   (interactive "kMove where? ")
 351   (let* ((class (solitaire-possible-move (lookup-key solitaire-mode-map dir)))
 352          (buffer-read-only nil))
 353     (if (stringp class)
 354         (error class)
 355       (let ((start (car class))
 356             (skip (car (cdr class)))
 357             (target (car (cdr (cdr class)))))
 358         (goto-char start)
 359         (delete-char 1)
 360         (insert ?.)
 361         (goto-char skip)
 362         (delete-char 1)
 363         (insert ?.)
 364         (goto-char target)
 365         (delete-char 1)
 366         (insert ?o)
 367         (goto-char target)
 368         (setq solitaire-stones (1- solitaire-stones))
 369         (solitaire-build-modeline)
 370         (if solitaire-auto-eval (solitaire-do-check))))))
 371
 372 (defun solitaire-undo (arg)
 373   "Undo a move in Solitaire."
 374   (interactive "P")
 375   (let ((buffer-read-only nil))
 376     (undo arg))
 377   (save-excursion
 378     (setq solitaire-stones
 379           (let ((count 0))
 380             (goto-char solitaire-end)
 381             (while (search-backward "o" solitaire-start 'done)
 382               (and (>= (current-column) solitaire-start-x)
 383                    (<= (current-column) solitaire-end-x)
 384                    (>= (solitaire-current-line) solitaire-start-y)
 385                    (<= (solitaire-current-line) solitaire-end-y)
 386                    (setq count (1+ count))))
 387             count)))
 388   (solitaire-build-modeline)
 389   (if solitaire-auto-eval (solitaire-do-check)))
 390
 391 (defun solitaire-check ()
 392   (save-excursion
 393     (if (= 1 solitaire-stones)
 394         0
 395       (goto-char solitaire-end)
 396       (let ((count 0))
 397         (while (search-backward "o" solitaire-start 'done)
 398           (and (>= (current-column) solitaire-start-x)
 399                (<= (current-column) solitaire-end-x)
 400                (>= (solitaire-current-line) solitaire-start-y)
 401                (<= (solitaire-current-line) solitaire-end-y)
 402                (mapcar
 403                 (lambda (movesymbol)
 404                   (if (listp (solitaire-possible-move movesymbol))
 405                       (setq count (1+ count))))
 406                 solitaire-valid-directions)))
 407         count))))
 408
 409 (defun solitaire-do-check (&optional arg)
 410   "Check for any possible moves in Solitaire."
 411   (interactive "P")
 412   (let ((moves (solitaire-check)))
 413     (cond ((= 1 solitaire-stones)
 414            (message "Yeah! You made it! Only the King is left!"))
 415           ((zerop moves)
 416            (message "Sorry, no more possible moves."))
 417           ((= 1 moves)
 418            (message "There is one possible move."))
 419           (t (message "There are %d possible moves." moves)))))
 420
 421 (defun solitaire-current-line ()
 422   "Return the vertical position of point.
 423 Seen in info on text lines."
 424   (+ (count-lines (point-min) (point))
 425      (if (= (current-column) 0) 1 0)
 426      -1))
 427
 428 ;; And here's the spoiler:)
 429 (defun solitaire-solve ()
 430   "Spoil solitaire by solving the game for you - nearly ...
 431 ... stops with five stones left ;)"
 432   (interactive)
 433   (let ((allmoves [up up S-down up left left S-right up up left S-down
 434                       up up right right S-left down down down S-up up
 435                       S-down down down down S-up left left down
 436                       S-right left left up up S-down right right right
 437                       S-left left S-right right right right S-left
 438                       right down down S-up down down left left S-right
 439                       up up up S-down down S-up up up up S-down up
 440                       right right S-left down right right down S-up
 441                       left left left S-right right S-left down down
 442                       left S-right S-up S-left S-left S-down S-right
 443                       up S-right left left])
 444         ;; down down S-up left S-right
 445         ;; right S-left
 446         (solitaire-auto-eval nil))
 447     (solitaire-center-point)
 448     (mapcar (lambda (op)
 449               (if (memq op '(S-left S-right S-up S-down))
 450                   (sit-for 0.2))
 451               (execute-kbd-macro (vector op))
 452               (if (memq op '(S-left S-right S-up S-down))
 453                   (sit-for 0.4)))
 454             allmoves))
 455   (solitaire-do-check))
 456
 457 (provide 'solitaire)
 458
 459 ;;; solitaire.el ends here